This invention relates to a bread baking device, and, more particularly, to a bread-baking device enabling the direct cooling of the driving motor employed in bread baking devices that knead raw ingredients, and bakes a loaf of bread.
Generally, bread baking devices are provided with a kneading blade rotatively installed on the bottom of a baking case as well as a large pulley connected to the driving shaft of said kneading blade, a small driving pulley connected to the driving shaft of the driving motor which is generally installed in a bonnet and a timing belt is located between said large pulley and the small driving pulley.
The revolutions of said driving motor are transmitted to said kneading blade through said timing belt with a reduced speed. The bread baking device kneads the raw ingredients places in said baking case with this driving force, and then bakes said raw ingredients with heating means such as heaters. In this bread baking device, since it requires a large motor-driving load to knead said raw ingredients, as a consequence, the heat generated by the motor's speed and the frictional heat between said belt and pulleys becomes rather large. Accordingly, some cooling means for the driving motor is required.
Up to this time, there have been provided countermeasures such as installing a motor fan exclusively for cooling the driving motor, or providing heat-shielding plates around said driving motor to avoid heat transmission from the generated heat during said baking process.
Unfortunately, in such conventional bread baking device provided with said exclusive motor-cooling fan, said device entails a more complex construction and larger size, as well as an increase in the number of part members when said exclusive motor-cooling fan is installed, which in turn then incurs higher production costs.
Furthermore, as said exclusive motor-cooling fan is usually installed apart from said heat-generating pulleys, there is also a problem in that it is insufficient to cool the dissipated heat owing to the friction of said belt. Also in said baking device provided with the shielding plates, there is an additional problem in that the cooling efficiency is inferior so far as expecting only natural heat convection of said shielding plates.
Taking the above-mentioned problems into consideration, this invention was intended to attain the object of providing a bread baking device not having an exclusive cooling fan as an extra, special part, and consequently enabling the low-cost production, by integrally shaping said cooling fan in one piece with said driving pulley mounted on the driving shaft of said driving motor, and by efficiently cooling the generated heat in said driving motor and the frictional heat generated in said belt by circulating air flow in accordance with the speed of said driving motor.